Shock absorber



F. H. ROYCE SHOCK ABSORBER March 4, 1930.

Filed Dec. 24, 1926 2 Sheets-Sheet \\\\\\\\\\\\\\\\\\\\\\mllr Q gyn/vento@ j." jf. a'yce gwu/ 5:

Imago F. H. ROYCE SHOCK ABSORBER March 4, 1930.

- Filed Deo. 24. 1926 2 Sheets-Sheet 2 gwwntow jf. joeyce.

WHS,

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Patented Mar. 4, 1930 UNITED STATES'PATENT OFFICE FREDERICK HENRY ROYCE, OF WEST WITTERING, NEAR CHICHESTER, ENGLAND, ASSIGNOR TO ROLLS-ROYCE LIMITED, OF DERBY, ENGLAND SHOCK ABSORBER Application led December 24, 1926,'Seria1 No. 156,966, and in Great Britain December 31, 1925.

The invention is a new and improved shock absorber, mainly useful in motor vehicles to mitigate the effect of road inequalities, of the form in which a hollow piston moves to and fro, under the influence of a lever connected to the shocked member to be relatively controlled, in a closed cylinder with a compression chamber to contain liquid at each end of the cylinder.

The conditions required for eilicient working of apparatus of the kind described above are that the compression chambers should be kept full of liquid, that all air or gas which may be accumulated therein shall be expelled, that the'required resistances (which may or may not be equal), dependent on the the application of the apparatus, shall be respectively oered to the movement communicated to the piston by the shocked member in each of the two directions of movement, and that such resistance shall be practically constant for all temperatures.

The object of this invention is to secure these conditions in a better manner than is done in any known apparatus. A further object of this invention is to reduce or eliminate side thrustyon the piston as it is moved to and fro.

According to this invention I make apparatus as follows :-On movement of the piston in either direction liquid in the chamber compressed passes through a conduit or conduits, which may be without the cylinder or through t-he piston itself, to the other chamber, separate and distinct conduits being pro* vided for the passage of liquid in each direction. The conduits connecting the two pressure'chambers are provided with spring loaded one-way valves oifering predetermined resistance, and if desired the springs are of diiferent power so that greater resistance will be offered to movement of the piston'in one direction than inthe other. The areas of the valve ports are of sufficient dimensions to render the variation of viscosity of the fluid used owing to change of temperature practically negligible. A reservoir is provided preferably at the side of the cylinder, with a conduit or conduits leading from the bottom thereof to the bottom of one or both, but preff portion a3 formed in such upstanding part erably both, of the pressure chambers, such conduit or conduits being provided with a one-way valve opening to admit liquid to the pressure chambers respectively for the purpose of replenishing such chambers should a vacuum occur therein through escape of oil or other liquid, and also a conduit from the top of a pressure chamber or other highest point of the compression system into the top of the reservoir, with means for adjusting the area thereof to a fine adjustment for the purposes of an air leak.

I also arrange for the purpose of eliminating or reducing side thrust on the piston that the application of force to the piston shall be (subject to a small margin of deviation) inthe line of its axis.

In the accompanying drawings a more detailed description by way of example of a shock absorber made according to my invention is illustrated.

Fig. l is a sectional elevation on line l-l of Fig. 2, Fig. 2 is a plan view of Fig. 1, Fig. 3 is an end sectional elevation on line 3-3 of Fig. 1 and Fig. 4 is a sectional view of an alternative form of construction for part of Fig. l.

a is a casting comprising a cylinder a1, an overhead outstanding part a2, a cylindrical 8l at right angles to the axis of the said cylinder al, a chamber or reservoir aL enveloping the middle of the cylinder al extending from the upstanding parta,2 down one side of and across the bottom of the cylinder, where it assumes internally a cylindrical shape. There is a gap a5 in the wall of the cylinder opening into the upstanding parta2 and extending round the cylinder c0-eXtensive with the reservoir. a6 is a boss formed on the casting in which is a cylindrical chamber a7 with a recess a8 in the lower end, communicating with the interior of the cylinder al via the drilled holes a and am. all is a cap closing the open end of the cylinder al when the working parts are assembled, secured by studs L12 and nuts als. a14 is a conduit drilled through the casting and into the cover a connecting the reservoir a4 with the respective ends of the cylinder constituting the compres- 100 sion chambers via drilled holes a, and am, and a (shown in dotted lines in Fig. 2]) is a conduit drilled through the casting connecting one end of the cylinder al with the cylindrical chamber a7, via hole als (shown in dotted lines in Fig. 2) drilled through the boss al", and a2 is a drilled conduit for the purpose hereinafterfappearing. b is a hollow piston having at the top a gap or hole b1 and a gap or hole at the bottom b2 and having formed at one end thereof a chamber Z13.' b4 is a Valve with a stem b5 fitting a guide hole in a boss b formed on the piston, 57 is a groove in the stem to prevent the same from being air bound, 58 is a spiral springclosing the valve and seating on the plate b9 which is secured by three screws b1", Zi are conduits drilled through bosses formed in the piston from one end of the pist-on to the interior of chamber b3, c is a rocking shaft actuated by the lever 01 integral therewith, which at its free end is operably connected to the shocked member to be controlled for example the axle of a motor car. The shaft c has an extended part c2 and a square part c3, and the shaft rotates in bushes c4 and c5, c is a packing, c7 a chamfered ring, cs a spiral spring pressing on such ring and c" is a cap secured to the casting by studs 01 and nuts 011. (Z is a lever with a split boss secured to .the square portion of the shaft c by means of pinch bolt Z1 and nut cl2, Z3 is an eye piece secured to'one end of the piston by a threaded extension passing through a hole in such end and a nut cZt, Z5 is a tab washer, als are links connecting the lever'oZ with eye piece Z3 and secured to such members respectively by shouldered pins Z7 riveted over at the ends. e is a valve seating on recess as under the influence of the spring e1, e2 is a plug, recessed in one end to locate the spring el and tapped to receive the screw e3 with a drilled hole e4, and a small drilled passage way controlled by a ball valve e5 constituting an air leak, but oering great resistance to the passage of oil, the plug e2 and the boss a are shaped to form an annular space e6 into which both the hole c4 and a2 open, thus forming a way for air escaping through the ball valve e5 to the reservoir.

In Fig. 4 is shown another example of the boss a6 and connected parts except that there isno ball valve e5, and the screw e3 is formed with an extension e7 extending down the air lea-k passage way but allowing the required clearance for the passage of air. The valve e is provided with a guide stem e8. extending down the hole a9 in the casting connecting the two holes a1", e9 is a groove in such guide to facilitate the movement of the valve e. f are ball valves, f1 are threaded plugs engaging tapped holes in the casting with extensions ]@2 to prevent the possible displacement of the balls. g is a hollow plug externally threaded 'and provided'with a flange `g1,'e'n

gaging a thread in the cylindrical part of the reservoir a4, and having three annular recesses g2 in the base of each of which are rows of holes g3, g4E is a plate closing the 'open end of the plug g, and g5 is a gauze lter. rlhe purpose of this plug and filter is to prevent 'the entrance ofv grit and other impurities into the valve passages from the reservoir. The oil passes from the reservoir through the gauze g5 into two of the spaces g2, through two rows of holes gsto the interior of the plug g, thence through one of the rows of z' is a stopperedoriiice through' which the apparatus can be supplied with oil or other liquid.

The spring el is more powerful than the spring 68 and greater resistance will be oifered to a movement of thefpiston to the right than to the leftthe right end of the cylinder being accordingly referred to as the high compression chamber and the left hand end as the low compression chamber.

The chamber at each end of the piston being filled and the reservoir supplied with oil, the operation of the apparat-us is as follows.

ln the event of a movement of the lever 01 in one direction the piston will be movedto the right compressing the oil in the high compression chamber, oil will be forced via the holes am through the valve e always encountering the resistance of the spring el, via the hole als and conduit a into the low pressure chamber. If the lever c1 is lmoved in the opposite direction the piston will be forced yto the left and oil in the low compression chamber will be forced via the conduits Z911 into the chamber Zthrough the valve b4 sistency in functioning caused by variations of viscosity of the liquid due to changes of temperature, the opening of the valve varying with the viscosity of the oil or liquidk used.

The eect of the arrangement of the lever eZ, link Z6 and eye piece Z3 is to ensuremove ment of the piston without undue load against the walls of the cylinders.

The effect of the arrangement of the reser-k voir and of the rocking shaft is to secure that all leaking of oil pastv the piston shall fall piston or through the gap b2. a

4If-througgghleakage past the piston or i into the reservoir either from the sides of the otherwise either compression chamber is not filled with oil the vacuum thereby occasioned will immediately suck oil from the reservoir via the conduits a, a valves e and conduit au.

I n the event of any air in either of the compression chambers it will travel to the highest part of the compression system and will be driven out through the small air leak and ball valve e5 or the small clearance past the stem e7 (shown in Fig. 4) as the case may be.

What I claim is 1. A shock absorber comprising a hollow double-ended piston in a closed cylinder with a liquid compression chamber at each end of the cylinder, two conduits connecting the compression chambers each controlled by a one-way valve admitting liquid to the chambers respectively, a reservoir to contain a quantity of the compression liquid formed on the side of and extending to the bottom of, the cylinder, a gap or opening in the wall between the cylinder and the reservoir, two conduits from the bottom of such reservoir to the compression chambers respectively, each provided with a one-way valve admitting liquid to the compression chamber with which it is connected, and mechanism including a shaft, situate without, and in a plane passing through the centre of, and normal to the axis of the cylinder, rocking in bearings attached to the cylinder, a suitably shaped hole in the wall of the cylinder nearest to the shaft and evenly disposed on each side of the said plane, a like suitably shaped hole in the wall of the piston, a lever secured to the said shaft projecting through the said holes to the centre of the piston, a link hinged to the free end of such lever and to one end of the piston, another lever projected from the said shaft without the cylinder, and operatively connected to the shocked member, whereby movement of the shocked member causes the piston to'move in one direction or the other.

2. A shock absorber comprising a hollow double ended piston in a closed cylinder with a liquid compression chamber at each end of the cylinder, two conduits connecting the compression chambers each controlled by a one-way valve admitting liquid to the chambers respectively, a small passage way from the uppermost part of the compression system to the outside of same permeable by air, but offering great resistance to oil or other liquid, and mechanism including a shaft,

situate without, and in a plane passing through the centre of, and normal to the axis of the cylinder, rocking in bearings attached to the cylinder, a suitably shaped hole in the wall of the cylinder nearest to the shaft and evenly disposed on each side of the said plane, a like suitably shaped hole in the wall of the piston, a lever secured to the said shaft projecting through the said holes to the centre of the piston, a link hinged to the free end of such lever and to one end of the piston, another lever projected from the said shaft without the cylinder, and operatively con-y nected to the shocked member, whereby movement of the shocked member causes the piston to move in one direction or the other.

3. A shock absorber as claimed in claim 2, the small passage way being provided with a one-way valve admitting air to escape from the compression system.

4. A shock absorber comprising a hollow, double ended, piston, a closed cylinder containing said piston and having a liquid compression chamber at each end, conduits connecting said compression chambers, one way controlling valves admitting liquid to the respective chambers, a reservoir for compression liquid, conduits leading from said reservoir to the respective compression chambers, each of said conduits being provided with a one-way valve for the admission of liquid to the compression chamber with which it is connected, a small conduit or opening from the uppermost part of the compression system to the outside of the same, permeable to air but offering resistance to the passage of the compression liquid and means opera.- tively connecting the shocked members to the piston.

5. A shock absorber as claimed in claim 4, one of the conduits connecting the two compression chambers being through the body of the piston.

6. A shock absorber as claimed in claim 4, the reservoir to contain a quantity of compression liquid being located on the side of the cylinder, a conduit from the bottom of such reservoir to one of the compression chambers with a one-way valve admitting liquid to such chamber, and means including a shaft operably connected to the piston, rocking in bearings free from the compression oil for operably connecting the shocked member to the piston.

7 A shock absorber as claimed in claim 4, the small conduit or opening being provided with a one-way valve admitting air to escape from the compression system.

8. A shock absorber as claimed in claim 4, with a lter between the reservoirv and the conduit, or conduits, leading therefrom tothe compression chambers.

In witness whereof I have signed this specification.

FREDERICK HENRY ROYCE. 

